Electric governor



April 26, 1932. R. T. CLOUD 1,855,703

ELECTRIC GOVERNOR Filed Jan. 6, 1930 Patented Apr. 26, 1932 UNITEDSTATES PATENT OFFICE RAYMOND '1. CLOUD, OF CHICAGO, ILLINOIS, ASSIGNORTO OBCHESTRAPHONE COH- PANY, OF CHICAGO,

ILLINOIS, A CORPORATION OF DELAWARE ELECTRIC GOVERNOR Application MedJanuary 6, 1930. Serial No. 418,978.

These improvements relate to electric governors.

The prime object of the invention is to provide a highly sensitiveelectric governor,

.-" namely one which is effective to control the circuit u on theoccurrence of slight variations in t e speed of the device to which thegovernor is connected, to the end that the speed of the shaft or otherrotatable dey1ce controlled may have but slight varlations from theconstant desired. It is an important object to provide such results in agovernor of few parts, of simple and durable construction and of lowmanufacturing cost; one not likely to get out of order; and one whereinadjustments may be made to adapt the instrument to a particular use.Other objects and advantages will appear hereinafter.

In the drawings Figure 1 is an end view of a motor and governor unit,partly broken away, showing the governor device in end face View; and

Fig. 2 is a medial vertical section through the governor device, as onthe line 2-2 of Fig. 1, the motor and some associated parts being infull side view but broken away.

The motor M and the governor marked as a whole G are shown as beingmounted on a common base 12 as a unitary mechanism. The motor shaftextending at 14 drives the governor device while the part thereofextending at 14a is to be understood as being in driving relation to themachine or mechanism the speed of which 15 to be rendered substantiallyconstant.

On shaft 14 is mounted a carrier shown as being of insulating material,for example hard rubber or bakelite. It may be of several. pieces but isshown integral and as consisting of the circular disc-like face plate15, a cylindrical hub 16 and a part 17 of reduced diameter. On this part17 are tightly forced two metal collector rings 18 and 19 of goodconductivity, such as copper, with an insulating spacing ring 20 betweenthem. T he parts 15,16 and 17 are bored with a hole 21 and a copper wireconductor 22 (shown diagrammatically) in that bore leads to thecollector ring 19 and is electrically secured thereto. The same carrierparts are similarly bored at 23 and the conductor 24 therein issimilarly connected with ring 18.

There -is a frame for holding brush devices 27 and 28 in associationwith the rings 18 and 19, this frame comprising a pair of U- shapedstrap iron members 30 and 31 secured to the base 12 and having securedto their tops a bar 32 extending above the disc or wheel 15. The bar 32is apertured to receive the cylindrical brush devices 27 and 28, asshown in Fig. 2, which brush devices are well known and contain nothingnovel in themselves. Each thereof has a carbon brush, marked 33 indevice 27 and 34 in device 28, with a spring 35 forcing the brushes intocontact with the rings 18 and 19 respectively.

Conductor wires 37 and 38 (shown diagrammatically) are secured to thesebrush devices 27 and 28 so as to be in good electrical communicationwith the brushes 33 and 34 respectively. The wire 37 is shown as beingone of the input wires for operating the motor 10. The wirer'38 is to beunderstood as being connected with the motor windings while inputconductor 40 is to be understood as being also connected with the motorwindmgs.

The circuit thus far described provides that input current may flowthrough conductor 40, through appropriate motor windings, thence throughconductor 38 to brush, 34, and thence through ring 19 to conductor 22.The return may be assumed to be first, conductor 24, then ring 18, thenbrush 33 and then conductor 37 back to the power line.

From the foregoing it will be clear that if the electrical circuit thusdescribed be suite ably controlled the speed of the motor will bemaintained substantially constant.

From Fig. 1 note that the opposed contact makers 44 and 45 are on theaxis of revolution of the shaft 14 and carrier wheel 15. They arespring-pressed into contact with each other by means shown as leafsprings 46 and 47 respectively, and these springsnre rigidly secured, asby rivets to lugs 48 and 49 respectively and which lugs may be deemedintegral with the disc 15. The same rivets 50 hold brackets 52 and 53each overlying an associated leaf spring, with adjusting screws 54 and55 arranged to bear upon the leaf springs respectively so as to produceany desired degree of pressure between the contact makers 44 and 45.

Weight members marked W comprise the threaded rods 56 and 57 and weightelement-s 58 and 59. The rods are rigidly secured to the leaf springs 46and 47 respectively and are directed away therefrom at a materiallygreat angle, ninety degrees as shown, and are substantially parallelwith plate 15 and are therefore directed across the path of theirrevolution. The weight elements 58 and 59 are threaded on the respectiverods and are held by locking nuts and 61. They may be adjust d outwardlyand inwardly. Considering both contact devices A and B to bemechanically the same, the adjustments at 54 and 55 and at 58 and 59should be the same respectively so as to preserve equality in thecooperative action of the two make-and-break devices.

If we now connect conductor 22 to one contact maker and connectconductor 24 to the other contact maker, as by wires 63 and 64respectively the contact makers 44 and 45 become switch elements in themotor circuit. By suitably making and breaking the circuit at thesecontacts the speed of the motor will be controlled.

With this understanding of the construction illustrated, which not onlyserves to explain the principles but is a peculiarly advantageousembodiment of the invention, note first that the governor device is freeof gravitational effects militating against a uniform action. As thedevice is illustrated in Fig. 1 the springs with their contact elementsand weights are subject to the maximum gravitationaleffects. That is tosay, gravitation tends to draw downward the contact device marked as awhole A, but the arrangement is such that its tendency is equally todraw downward the device marked as a whole B, and thus to any extent(and it is a very appreciable factor) that gravitation acts on onemember the same action on the other member maintains the contact makers44 and 45 in the same relative position with respect to each other.

A governor device operated on a vertical axis does not always containthis gravitation problem, but the provision of means designed merely tochange the direction of rotation of a horizontal shaft to be controlledwould be highly objectionable for many reasons. Note that I avoid allgearing and the possibility of lost or irregular motion at any placebetween the motor and the governor.

Next observe that the contact makers and their spring connections(omitting the weight elements) are substantially free from the action ofso-called centrifugal force, owing to the substantially radialarrangement of the springs. Note also that they are substantially freeof counteracting inertias. Assuming disc 15 in Fig. 1 to be rotating inthe direction of the arrow the inertia of the contact makers themselvestendim to move them relative to the axis of rotation is substantiallynil, assuming them to be like and the axis to pass medially betweenthem. In any event (still assuming the weight elements removed),whatever inertia may affect the contact makers and their associatedspring supports 46 and 47 affects each in a direction tending to movethe contact makers toward each other. I deem this very slight tendencyto be neutralized by a slight tendency of the contact makers to moveapart by centrifugal action due to such factors as that the center ofgravity of the contact makers is slightly off of the axis of rotationand the springs 46 and 47 are not exactly radial.

It is not strictly essential that the contact makers and their springssupports be substantially free of the total effects of inertia, momentumand centrifugal force, or of either of them, for the device employs bothinertia and momentum acting tangentially and centrifugal force actingradially as factors in the desired control, and some thereof could bepermitted to inhere in these structural parts. If, however, these partsbe free or substantially free of influences like gravitation, inertia,momentum and centrifugal force it would appear that their operation inpractice could be expected to be more uniform under the influence ofdefinite control elements such as the weight members W than I if therewere various cooperating or antagonizing influences entering into theequation. The gravitational effect would be especially objectionable,and the devices A and B should therefore be as nearly exact counterpartsof each other as possible.

Considering now the effects of the weight members W, their arrangementis such as to introduce. very distinctly the factors of inertia,momentum and centrifugal force. On accelleration of the shaft 14 theinertia of members W causes them to lag or seemin 1y move back relativeto the carrier. On fiecelleration of the shaft 14 momentum carries themembers V forward relative to the carrier. The lag movement flexes thesprings 46 and 47 and separates the contact makers 44 and 45 while theforward momentum movement closes them or permits the springs to closethem. .Since the respective lags oradvances of the members W aresimultaneous and equal the balance of the parts is not disturbed, and,further, since these weight movements always affect the contact makersin opposite directions, a slight lag or advance movement effects a rapidseparation or meeting of the contact members.

The outward centrifugal action of the weight members, being in oppositedirections for devices A and B, tends to effect a separation of thecontacts. On decelleration of shaft 14 the loss of outward centrifugalforce permits thesprings to close the contacts.

The radial or centrifugal action is not alone sufiicient for a notablysensitive control since that action is concomitant with speed variationsat a given time already under way. The lag or other tangential relativemovement is different in this respect, being initiated immediately thereis a change in speed.

speed, and that property is used Tangential momentum and inertia arelikewise not suflicient alone for accurate control. For one thing theydo not provide a maximum or a minimum speed limit, but concernthemselves only with a. change of speed. The radial or centrifugalaction can limit the in the device shown.

For illustration of the action, let us suppose the adjustments at theweight members W and at screws 54 and 55 to be such as to provide amaximum speed of one thousand revolutions per minute of the shaft 14.When the current is applied to the circuit shown the motor will rapidlypick up from zero to the speed mentioned, for the tension of the springs46 and 47 will not be overcome by the actions of weights W during thepreliminary starting increments. At approximately one thousandrevolutions per minute a substantially balanced condition would existbetween the forces tending to separate the contacts and the forcestending to hold them together. If dependence were now had upon thecentrifugal movements alone we would find that the speed would varyconsiderably.

f we assume that the centrifugal action would break the circuit at 1000R. P. M., then the ensuing decrement in speed would have to be under waybefore the loss of centrifugal force would operate to permit the springsto close the gap at the contact makers, and then the speed would have tocontinue its 1 increment for awhile before the centrifugal action wouldagain operate to break the circuit.

With the tangential action included, however, the efl'ects are quitedifferent. We are assuming the speed to be approximately at thepredetermined rate and with the forces operating on the contact makerssubstantially balanced. A change of speed now occurs and the tangentialaction at once becomes effective. Assuming the speed of the shaft 14 tobe reduced, the Weights W move forward relative to the carrier and thecontacts are closed almost instantly with the change of speed. Assumingthe speed of shaft 14 to be increased, the lag operates almost instantlyto open the circuit.

Throughout the entire operation, however, the centrifugal action is ineffect. The

springs were adjusted to exert considerable upon this condition pressurebetween the contact makers. The

stantially a state of equilibrium between the springs and thecentrifugal force. The extreme nicety of control occurs through theintroduction of the tangential action to play of substantial balance.Substantially the slightest increment or decrement in speed affects theweight members tangentially, and it thus happens in practice that thecircuit is made and-broken incessantly at the contacts-apparently withperfect regularity and I would estimate as often as at least fifty timesa second in the tests I have made. i

As indicating the effectiveness of this governor I may mention that apurely hand-made device, made substantially to scale with thesedrawings, but without the usual refinements in construction or anyattempt to balance otherwise than as would result from the assembly ofthe substantially like parts, showed a Variation in shaft speed, in acontinuous test of thirty-six minutes, of about one revolution infifteen hundred, or a variation from constant of about one-fifteenth ofone percent.

A more accurately made device would show an even better approximation ofconstant speed. The test was made with a squirrel-cage type of inductionmotor with shaded poles.

In practice the location of the weight elements W on the springs mayvary from a place opposite the contacts respectively (making a radialarrangement) inward toward the supports 48 and 49, or they could becarried by extensions of the springs beyond the contacts. It will beclear also that the principles and combinations thus set forth may beembodied in various other kinds or types of mechanisms. I thereforecontemplate as being included in the present invention all such changes,departures and variations from what is thus specifically illustrated anddescribed as fall within the scope of the appended claims.

I claim:

1. An electric governor comprising a rotatable carrier having weightmembers and contact members, the weight members being mounted for radialand tangential movements relative to the carrier under the influence ofspeed variations in the carrier, the contact members being under thecontrol of said relative movements of the weight members, and means forconnecting the contact members in a circuit to be controlled.

2. An electric governor comprising a rotatable carrier, oppositelyarranged weight members carried for revolution by the carrier andmounted for tangential and radial movements relative to the carrierunder the influence of speed variations in the carrier, oppositelyarranged contact members associated with and under the control of theweight members respectively to make and break a circuit under theinfluence of such relative movements of the weight members,

and means for connecting the contact members in the circuit to becontrolled.

3. An electric governor comprising in combination a rotatable carrier,contact makers carried thereby, means for connecting the contact makersin a circuit, resilient means pressing the contact makers intocontactmaking position to complete the circuit, and weight meansassociated with each of the contact makers to open and close thecircuit, said weight meansbeing mounted for revolution by the carrierand for movements relative thereto having a tangential component and, aradial component'under the influence of speed variations in the carrier.

4. An electric governor comprising a retatable carrier, a pair ofoppositely disposed spring-pressed contact makers, a pair of weightmembers associated with the contact makers respectively and being.severally mounted to move relative 'to the carrier with a tangentialcomponent and with a radial component under the influence of variationsin the speed of the carrier to move the contact makers relative to eachotherto make and break a circuit, and means for connecting the contactmakers in the circuit to be controlled.

5. An electric governor comprising a rotatable carrier, weight memberscarried for revolution by the carrier and being mounted for tangentialand radial movements relative to the carrier under the influence ofspeed variations in the carrier, a circuit, and contact 'memberssubstantially on the axis of carrier revolution and under the control ofsaid weight members respectively and operative to make and break thecircuit under the influence of such relative movements of the weightmembers.

6. In an electric governor the combination of a horizontal shaft, acarrier mounted thereon, a pair of opposed contact makers meeting eachother face to face substantially on the axis of shaftrotation, springmeans carried by the carrier and adapted to force the contact makersresiliently toward and into contact with each other, oppositely-disposedwei ht members mounted for rotation by the carrier and for movementsrelative thereto having a radial component and a tangential component,the weight members being operatively connected to the contact makersrespectively to move them toward or away from each other when the weightmembers move relatively with respect to the carrier, means for adjustingthe spring members respectively, and means for connecting the contactmakers in a circuit to be controlled. j

7. In an electric governor, the combination of a substantiallyhorizontal shaft, a carrier mounted for rotation on said shaft, a pairof leaf spring members mounted on the car- -rier in zip roximatelyradial direction there-.

with, the rec ends of said springs being adjacent to each other close tothe axis of shaft rotation, a contact maker carried by each springmember adjacent to said axis of rotatlon, means for adjusting thetension of said spring members respectively, weight elements carried bysaid spring members respectively, the weight elements being positionedeflectively a materially great distance from the spring membersrespectively and in line substantially at right angles to the springmembers respectively whereby the weight members will have movementrelative to the carrier in both radial and tangential directions underthe influence of speed variations in the carrier, and means forconnecting said contact makers in a circuit to be controlled.

8. In an electric governor a horizontal rotatable shaft, a carrier onthe shaft, :1, pair of leaf spring members secured to the carrier andextending substantially radially inward,

contact-making means associated with said contact-making means in acircuit to be controlled, and weight members carried by the springmembers respectively and being mounted for movements relative to thecarrier in both tangential and radial directions under the influence ofspeed variations in the carrier.

9. In an electric governor the combination of a shaft, a carrier rotatedthereby, an elec tric make-and-break device carried by the carrier andhaving contact members substantially on the axis of shaft rotation andadjacent to the carrier, and weight means carried by the'carrier forrotation and operatively associated with said make-and-break devicesrespectively, said weight means being mounted for movements relative tothe carrier with tangential components and with radial components, meansfor connecting the make-andbreak devices in a circuit, saidmake-andbreak devices being under the control of the tangential andradial relative movements of said weight members.

10. An electric governor comprising a rotatable carrier, a pair ofelongated spring elements rigidly secured to the carrier and di- 1transverse to the direction of carrier rotation, 1

a weight carried by each of said r'ods at a substantial distance fromthe spring elements respectively, and means for connecting thecontactmakers in a circuit to be controlled.

11. An electric governor comprising a roments transversely to thedirection of carrier rotation, an adjustable weight carried by each ofsaid rods at a substantial distance'from the spring elementsrespectively, and means v 151 I Y to be controlled.

for connecting the contact makers, in a circuit 12. An electric governorcomprising a carrier mounted for rotation, and a pair ofoppositely-disposed and coacting make-andbreakdevices carried by thecarrier, each of said make-and-break devices including a weight elementhaving tangential and radial components of movement relative to thecarrier under the influence of speed variations of the carrier,

13. An electric governor comprising a carrier mounted for rotation, apair of oppositely-disposed and coacting spring-tensioned contact makerscarried by the carrier, means for adjusting the spring tension of thecontact makers, each ofsaid contact makers having a weight elementmounted for tangential and radial movements relative to the carrierunder the influence of speed variations of the carrier, and means foradjusting the weight elements.

14. A rotatable electric governor having contact means for controlling acircuit, control means for the contact means including weight meansmounted as part ofthe governor for rotative movements and also fortangential and radial relative movements under the influence of speedvariations of the governor, the contact means and the control meansbeing operatively connected together by means includingspring-tensioning means operating normally to maintain the contact meansclosed to complete the circuit at the contact means, the tension of saidspring tensioning means and said weight means being proportioned wherebywhen the governor speed reaches a predetermined amount the bar carriedby said carrier for movement therewith and also for radial andtangential relative movements under the influence of speed variations inthe carrier, the weight member being operatively connected to thecontact member to move the same into circuitbreaking position when thecentrifugal force acting on the weight member reaches a given amount,the spring tension of the contact maker being such as substantially tobalance said given amount of centrifugal force, said weight member beingoperatively connected to the contact maker to control the contact makerby a tangential movement of the weight member due to a variation in thespeed of the carrier when said sprin ten-' $1011 and said centrifugalforce are su stantially in balanced relation to each other.

RAYMOND T. CLOUD.

tension of the spring-tensioning means is substantially balanced by thecentrifugal orce acting radially on the weight means,

' the arrangement providing that when the centrifu al force of theweight means and I the tension of the tensioning means are thussubstantiallybalanced the tangential action of the weight means underthe influence of a variation in governor s ed will control I the contactmeans to contro the circuit.

1 5. An electric governor which includes a spnng-tensioned contactmaker, a rotatable carrier for a weight member, a weight mem-

